Metal–semiconductor–metal photodiodes fabricated from thin-film diamond

Abstract

A metal–semiconductor–metal Schottky barrier photodetector has been fabricated on a “hydrogen-doped” surface-conducting chemical vapor deposition (CVD) diamond. The device is fabricated in one step by forming two back-to-back aluminum Schottky diodes on the p-type surface. This simple process is compatible with previously reported metal–semiconductor field-effect transistor fabrication on this type of CVD diamond and offers the prospect of the monolithic integration of a ultraviolet detector and active circuitry. Preliminary electrical and optical characteristics of the device have been measured, including the spectral response over the range 180–800 nm. The device exhibits a linear response with the applied optical power at 220 nm, operates at a bias of only 2 V, and shows visible blind characteristics, with a spectral discrimination of three orders of magnitude as determined from the ratio of 200–550 nm responses.

A Comprehensive Review of Semiconductor Ultraviolet Photodetectors: From Thin Film to One-Dimensional Nanostructures

“…Due to the high resistivity of the epilayer, the photoconductor fabricated on an oxidized epilayer had a low dark current (1 pA) at 20 V. The dark I-V curve disclosed a space-charge-limited-current behavior, consistent with Ohmic contacts to a highly resistive material, as shown in Figure 10 [92]. …”

“…The MSM photodiode has the advantages of fabrication simplicity, high bandwidth capability, and suitability for integration with field effect transistor. Al or WC were used as the back-to-back contacts [92,93]. The state-of-the-art diamond MSM photodetectors including ours had been fabricated with the electrode spacing in the scale of several microns [91].…”

Electronics and sensors based on pyroelectric AlGaN/GaN heterostructures

“…For a sheet carrier concentration of 2.1x10 12 cm -2 , a maximum mobility of 28000 cm temperature mobility, µ 2DEG , is increasing with increasing sheet carrier concentration due to enhanced screening of charged defects, a decrease of 2DEG mobility is observed for AlGaN/GaN heterostructures with increasing sheet carrier concentration, n s (µ 2DEG ∝ n s (-2.1±0. 2) ), corresponding to an increase of the Al content in the barrier. These observations were confirmed by Shubnikov-de-Haas (SdH) experiments as discussed in the following.…”

“…On the one hand, the large band gap ensures an increase of device performance due to a low number of optically or thermally generated carriers (e.g. "solar blind" UV detectors [1][2][3], high temperature gas sensors [4], etc.). On the other hand, the strong chemical bonding between the constituent atoms not only leads to a large band gap, but at the same time gives rise to a quite favorable mechanical, thermal, and chemical stability of this class of materials.…”

Large deep-ultraviolet photocurrent in metal-semiconductor-metal structures fabricated on as-grown boron-doped diamond

“…[2][3][4][5][6] Only a few reports have characterized the UV photodetection properties of high-quality undoped single-crystal homoepitaxial CVD diamond. 7,8 In this study, we investigate the UV photosensitivity of the MSM Schottky contacts fabricated on as-grown borondoped homoepitaxial diamond.…”